Does a muffler rob much power from a lyc 435 when installed on a 12D? I had one installed when I first got my D model and now I'm wondering how much power I'm giving up. (should have thought of that before) I know the helicopter is still loud as heck so I'm not really saving the neighbors ears that much. Anybody know?

I operate a couple of E's with mufflers, no power loss, very little noise reduction in the cabin, but big reduction on the outside. Have to make all the stuff now Hiller can't supply. Be careful flooding engine, they are easy to blow up. Great for heating up tortillas on cold days. I believe the muffler kit makes a E one of the quitest machines around, should do the same for a D.

That's good news and thanks for the tip on flooding. I'm thinking about converting to an E when my engine needs o/h. I could sure use a little more power. The thing that makes me think twice is the tortional coupling required for the E that costs 10K+ and needs replacement after 5 yrs. I'd never time one out before I needed another. Any thoughts?

Don't worry about the 5 yr life on the coupler, that's just a Lord deal. The problem with the couplers being made now is that they don't last. Lord must have changed the rubber compound, because the old ones used during the time the Army had these machines would last two to three runs at least. I have a hard time getting 1500 hrs on one of the new ones. If I could find a new old one made around the late 60's to early 80's, I would gladly pay 10K for it. If your not working heavy loads I would stay with the D. The 435 is a smooth running engine.

Nieuport28 wrote:I operate a couple of E's with mufflers, no power loss, very little noise reduction in the cabin, but big reduction on the outside. Have to make all the stuff now Hiller can't supply. Be careful flooding engine, they are easy to blow up. Great for heating up tortillas on cold days. I believe the muffler kit makes a E one of the quitest machines around, should do the same for a D.

For the record, the factory does have mufflers available in stock. The kit is $16,809.05 (subject to change of course because who knows how long this post will be around). I know it sounds a little pricy but its quality built from the best materials and will last the life of the machine if properly maintained.